Table 7 and Figure 6 show the results of tensilestrength of concrete at 28 days. It is clear from the bar chart that the higher the amount of polystyrenebeads in concrete mixture, the lower the tensilestrength. Relative tensilestrength of lightweight concrete compared to normal weight concrete are shown in Table 8, while Table 9 represents the comparison between tensilestrength and 28 days compressivestrength of all concrete mixtures as well as the ratio between them.
Twenty five 150X150mm cubes and 150mm diameter 300m high were cast out of which three cubes each were used to determine the compressivestrength and three cylinders each were used to determine the split tensilestrength of High performance Concrete. Mix ratios were shown in Table-1. Table-2 shows the detail of cube casting mix ratio. Table-3 shows the Detail of Cylinder Casting mix ratio. All High performance concrete was made with mix design procedure using Trial and error method. IS 516:1959 code represents Flow test (workability) was carried out by slump cone test as described for cement concrete. After the flow test, fresh concrete were placed in respected mould as described in the IS 516.-1959. The fresh concrete was cast and compacted by the usual methods used in the case of Portland cement concrete. The specimens were left standing for 1 day and then cured. After the curing period the specimens left at the room temperature for about an hour and ready for testing. Thus the compressive strengths and tensilestrength of concrete were tested at the same day in accordance with IS 516.-1959. The reported strengths were the average of the three specimens.
laboratory study on the tensilestrength behavior of HSC, direct tensile testing was performed despite difficulty and no criteria for calculation, he reached the following:: flexural tensilestrength of HSC is approximately1/8 of compressivestrength, split tensilestrength of HSC is approximately1/12 of compressivestrength and direct tensilestrength of HSC is approximately1/15 of compressivestrength, The properties of tensilestrength of HSC were not widely studied except for limited studies,. In 2010 Al-Azzawi found that HSC with fibers has a higher tensilestrength than HSC concrete without fibers as in the following relationship: = 65.7√ +4.2F& = 0.93√ +4.5F, where F fiber factor, . In 2014, A. Mohd said that the power model are more accurate than the square root model in the relationship between the compressivestrength and tensilestrength of the concrete .
compressive and split tensilestrength of chopped basalt fiber reinforced concrete of M20 grade concrete. A coir fiber, glass, steel, polypropylene, polyester fibers are used in concrete to gain strength to the concrete. In this study, the compressive and splitting tensilestrength was studied after introducing chopped basalt fibers. In this research, 12 mm long and 13 μm in diameter basalt fibers were used as well as the cubes and cylinders have casted with basalt fiber reinforced concrete for 0.5 %, 1.0% and 1.5% of basalt fibers by the weight of cement along with ordinary concrete. The compressive and split tensile strengths are carried out on cubes and cylinders by using Compressive Testing Machine (CTM) and Universal Testing Machine (UTM). And lastly all the results were compared and analyzed with ordinary concrete, and it shows that, basalt fiber reinforced concrete will improves the compressive and split tensilestrength of the concrete.
3. METHODOLOGY AND PROCEDURES OF WORK Initially the materials (Cement, Fine aggregate , Coarse aggregate 20 mm size and Nano-silica ) used are tested and the test results are taken. Cubes and Cylinders are casted of M25 mix design concrete for varying percentage of Nano Silica and they are used for determining the Compressivestrength and Split tensilestrength of concrete using varying percentage of Nano Silica. Tests are conducted using Compression testing machine and also cylinders are tested using Split tensile testing machine.
0%, 0.2%, and 0.6% respectively. The splitting tensilestrength at 7 days increases from 6.176 N/mm 2 to 8.386 N/mm 2 as the percentage of fibre increases from 0% to 0.4%.
A composite material that consists essentially of a binding medium, such as a mixture of Portland cement and water, within which are embedded particles or fragment, usually a combination of ﬁne and coarse aggregate . The tensilestrength of concrete is much lower than its compressivestrength, it is typically reinforced with steel bars; reinforced concrete. Concrete has better resistance in compression while steel has more resistance in tension. Conventional concrete has limited ductility, low impact and abrasion resistance and little resistance to cracking. A good concrete must possess high strength and low permeability. Hence, alternative Composite materials are gaining popularity because of ductility and strain hardening. To improve the post cracking behaviour, short discontinuous and discrete fibres are added to the plain concrete. Addition of fibres improves the post peak ductility performance, pre-crack tensile
The use of blended cement is becoming common in these days owing to the attempts made by the researchers in the direction of utilization of materials, which are available in natural abundantly. The new additives fly ash and polypropylene (Recron -3s) fibers, which is tried in recent times without any scientific study was found to be satisfactory. While, there is much to be done in order to standardize the properties of the said additives. The experimental study of this investigation consists of design of M40 grade concrete mix. The mix was worked out giving certain proportions by keeping the obtained water- cement ratio constant as 0.40. Concrete blends, viz. conventional concrete blends with differing rates of fly ash (0, 20, 30 and 40%) as cement replacement material were examined. Simultaneously the fibers were varied from 0 - 1% for each of the fly ash replacement in the concrete mix. The compressivestrength and split tensilestrength test were carried out at the ages of 7, 28 and 56 days. The impact of fibers and fly ash as cement replacement material on mechanical properties were analysed and compared with conventional cement concrete. This paper briefly shows the compressivestrength of cubes and tensilestrength of cylinders of all the concrete blends explored at 7, 28 and 56 days.
content for both compressive and split tensilestrength was obtained, which is at 0.3%(medium dosage) fibre content and 30mm length. NFRC shows a higher compressivestrength and higher tensilestrength compared to the controlled concrete because when FRC cracks due to load being applied to it; the fibres were activated, arresting the formation of further cracks. When using higher dosage the strength decreases as the concrete workability decreases which will trap more air than highly workable concrete, creating larger voids and honeycombed surface and the existence of this large air voids reduces the strength of concrete due to less friction and poor interlocking between aggregates. The crack bridging effect of fibres that are existent at the crack face allows additional stress to be taken by the Post-Failure CompressiveStrength.
Along with technological developments in the field of construction, using concrete materials are commonly used as a material that supports the building structure . Theoretically, the concrete material is able to resist high compressivestrength, but not good enough to resist tensilestrength. The value of the density normal concrete which ranges between 2200-2400 kg/m 3 , this will affect
In this study, structural properties of foamed aerated concrete with and without pulverized bone were investigated. These properties are: workability, plastic and testing densities, compressivestrength, and tensilestrength at the design density of 1600kg/m 3 . The tensilestrength was evaluated by subjecting 150 x 150 x750mm unreinforced foamed concrete beams to flexural test and 150x300mm cylinder specimens were subjected to splitting test. 150mm cube specimens were used for the determination of both the compressivestrength and the testing density of the foamed aerated concrete. The plastic density was investigated using a container of known volume, and its workability determined using the slump test. The pulverized bone content was varied from 0 to 20% at interval of 5%. The specimens without the pulverized bone served as the control. At the designed density of 1600 kg/m 3 , the results for the control specimens at 28-day curing age are 15.43 and 13.89N/mm 2 for air- and water-cured specimens respectively. The modulus of rupture and splitting tensilestrength are 2.53 and 1.63N/mm 2 respectively. The results for specimens with pulverized bone did not differ significantly from the specimens without pulverized bone. From the results of this investigation, it can be concluded that foamed aerated concrete used for this study has potential for structural applications. Also pulverized bone can be used to reduce (partially replace) the quantity of cement used in aerated concrete production; thus ridding our environment of potentially harmful wastes, as well as reduce the consumption of non-renewable resources.
Geosynthetics have become very good established construction materials for most of the civil engineering works, because of their improving properties it is used worldwide. Navadays it has been utilised to carry out to solve the critical problems in each and every engineering aspects. The experiment and research is carried out by various departments and development of this new technique is carried out. Because of this significant application of geosynthetic this paper focusing on the development of its application in the construction field as the replacement to the steel used in the concrete as reinforcement. Geosynthetics are sheet of tensile elements with a regular network of apertures, usually constructed as polyethylene. The most common use is for reinforcement of unstable soil and waste masses. Geosynthetics are synthetic products used to stabilize terrain. This includes eight main product categories they are geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells and geocomposites. Geonets are formed by a continuous area extrusion of parallel sets of polymeric ribs at acute angles to one another.
cent by volume of glass fiber mixed into cement or cement sand mortar. This glass reinforced cement mortar is used for fabricating concrete products having a sections of 3 to 12 mm in thickness. Methods of manufacture vary and include spraying, casting, spinning, extruding and pressing. Each technique imparts different characteristics to the end product. Spray deposition constitutes a very appropriate and by far the most developed method of processing. In the simplest form of spray processing, simultaneous sprays of cement or cement sand mortar slurry and chopped glass fiber are deposited from a dual spray gun into, or onto a suitable mould. Mortar slurry is fed to the spray gun from a metering pump unit and is atomised by compressed air. Glass fiber is fed to a chopper and feeder unit that is mounted on the same gun assembly.
Mix design of M20 grade concrete was carried out according to IS: 456-2000. Total 60 specimens concrete were casted consisting 30 cubes and 30 cylinders. 6 cubes and 6 cylinders of each proportion were casted. Conventional, Base, 0.1%PVA, 0.2%PVA and 0.3%PVA were the 5 set of proportions. Conventional concrete contained water, cement and aggregates without any admixtures. Base concrete contained water, cement, aggregates, bentonite replacing 30% cement, 0.1% of jaggery and sugarcane molasses without replacing cement. 0.1% PVA concrete contained base concrete plus 0.1% PVA by weight of cement without any replacement and same for 0.2%PVA and 0.3%PVA composite concrete.
Also it was observed that the rate of increase in strength is relatively low as compared with the rate before 28 days. This is in line with expectation for concrete and those containing pozzolanic material in general. It can be concluded from the above result that the improvement of tensile splitting strength of concrete with the incorporation of BLA is effective with 5 % replacement of the cement with BLA. The improvement in tensile splitting strength at early age and lower BLA (5 % content) replacement could be attributed to the initial filling of the voids by BLA at higher levels of BLA (i.e. ˃ 5 %) substitution, the voids must have been filled while the excess cause reduction in strength. This finding was reported by Bhanja and Sngupta (2002), which stated that initial filling of voids by silica fume significantly improves the tensilestrength, but at higher levels, the improvement decreases as shown in Figures 6.and 7.
techniques, the demand for construction materials increases day by day. There is a strong need to utilize alternative materials for sustainable development. The usage of partial replacement of coarse aggregate using polystyrenebeads in concrete gives prospective solution to building construction industry. Polystyrenebeads are the waste material obtained from packaging industries. This paper handles comparison of concrete which partially replaces coarse aggregate by polystyrenebeads with conventional concrete blocks. The result shows that amount of the polystyrenebeads incorporated in concrete influences the properties of hardened concrete. Also, the compressivestrength, Split tensilestrength and Flexural Strength for M30 & M40 with 5%, 10%, 15%, 20%, 25%, & 30% replacement of coarse aggregate. The workability of mix is very high at a low water/cement ratio.
In this they had concluded that Increase in the EPS beads content in concrete mixes reduces the compressive and tensilestrength of concrete. All the EPS concrete without any special bonding agent show good workability and could easily be compacted and finished. The replacement by using EPS has shown a positive application as an alternate material in building non-structural members, and it also serves as a solution for EPS disposal.
various proportions of granite powder and polypropylene fibers on the properties of concrete. This paper examines the compressive, split tensile and flexure strength of concrete. River sand is the most commonly used fine aggregate in making concrete. But extensive use and high transportation cost of sand gives rise to expense, so to cut down the cost of sand, granite powder is used as a replacement of sand with variable proportion of 10%, 20% & 30%. Granite powder is an industrial waste which is available in abundance. Fixed proportion of Polypropylene fiber was added to the concrete which is 0.25 percent of the weight of cement. Polypropylene fiber is mainly used for reinforcement of concrete to improve the tensilestrength of concrete so as to avoid explosive spalling at elevated temperature, thus making it fire resistant. The main aim of this experimental program is to design concrete of grade M45 and then to study the effect of polypropylene fiber and granite powder at high temperature of 300˚C. After performing the experimental program, the results show that the maximum compressivestrength of concrete having 20% proportion of granite powder show improved properties into reference to the plain M45 grade of concrete.
1.4 Structural and nonstructural lightweight concrete
Lightweight aggregate concretes (LWAC) can be used for structural applica- tions, according to the American Concrete Institute (ACI). To be considered as structural lightweight concrete (SLWC), the minimum 28-day compressivestrength and maximum density are 17 MPa and 1840 kg/m 3 , respectively. The practical range for the density of SLWC is between 1400 and 1840 kg/m 3 . LWC made of a material with lower densities and higher air voids in the cement paste are considered as nonstructural lightweight concrete (NSLWC) and will most likely be used for its insulation and lower weight properties. LWC with compressivestrength less than 17 MPa is also considered as NSLWC. There are several benefits with using LWAC such as improved thermal specifications, better fire resistance, and dead load reduction which results in lower cost of labor, transportation, formworks, etc., especially in precast concrete construction industry. With the reduction of the concrete density, the properties of the concrete change fundamentally. For two specimens of concrete with the same compressivestrength, but one made of LWC and the other one made of NWC, the tensilestrength, ultimate strains, and shear strengths are all lower in LWC than NWC, while the amount of creep and shrinkage is higher for LWC. LWC are also less stiff than the equivalent NWC. However, there are benefits in using LWC such as reduction in dead load that results in slight reduction in the depth of a beam or slab. It is also observed that the elastic modulus of LWC is lower than the equivalent strength of NWC, but when considering the deflection of a slab or beam, this is counteracted by the reduction in dead load.
Construction industry plays an important role for the construction of buildings, bridges, tunnels and also for developing infrastructures. Concrete is a most commonly used construction material. The utilization of concrete or cement based material is quite ancient. With the passage of time the significance of concrete has grown and the limitation of concrete have been gradually cut, making the concrete more durable and with a higher performance. A very important development that took place in the history of concrete was the use of reinforced bars in concrete for structural elements. This technique was quite efficient in terms of resisting the macro cracks in concrete and in imparting bending strength in flexural members. The reason was to somehow affect the low tensilestrength of concrete by strategically placing the bars. However, concrete as a material remained weak in tension and brittle.
Abstract: Light weight concrete is a mixture of EPS (expandable polystyrene) beads i.e. light weight aggregate and plastic beads and OPC (Ordinary Portland Cement). EPS beads are sufficient enough to meet the requirement of light weight concrete. The cube containing EPS beads does not show enough compressivestrength. Light weight concrete made using EPS beads and plastic beads are effectively used in partition walls, panels and other non-load bearing elements of the buildings as they provide required compressivestrength. These elements shows good thermal insulations and durability. Light weight concrete can be made in any size and shape as per the requirement.